The present disclosure relates generally to a trip system for a circuit breaker, and particularly to an apparatus and method for adjusting a trip unit of the trip system.
Electrical circuit breakers may employ a variety of trip units for sensing an electrical current and for initiating a tripping action at the circuit breaker, including bimetallic, magnetic, and thermal/magnetic trip units. Magnetic trip units may include c-shaped magnets, oil-filled dashpots, coil-type solenoids, and the like. Circuit breaker manufacturing processes employing such trip units may include a calibration routine to properly coordinate the responsiveness of the trip unit to an electrical current and to properly adjust for dimensional variations and tolerances among and between the circuit breaker components. One such calibration routine involves the setting of different parameters, such as a magnetic air gap and a mechanical air gap for example. However, the adjustment of one parameter may effect the adjustment of another parameter, which may then need to be readjusted. Accordingly, there is a need in the art for a trip system for a circuit breaker that overcomes these drawbacks.